This paper describes a technique that retrieves soil moisture from monopolarized SAR data. The technique uses SAR data obtained by the Japanese Earth Resources Satellite (JERS-1) and two empirical models. One relates the backscatter coefficient with the complex permitivity (Dubois's model), and the other relates the complex permitivity with soil parameters such as soil moisture (Hallikainen's model). First, the SAR data were calibrated to obtain the backscatter coefficient and the Dubois's model was inverted to achieve the complex permitivity. The insertion of estimated values of roughness was necessary to use the inverted equation with JERS-1 SAR data. Using these results and the Hallikainen's model, the soil moisture was calculated and compared with field measurements. The results were found to be moderately accurate and the inverted models were quite sensitive to the precision of the estimated values of roughness.
synthetic aperture radar; water content; corn; retrieval models